Valve for compressors



No. 622,344. Patented Apr. 4, I899.

F. W. GUBDON.

VALVE FOR GOIIPRESSORS.

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SPECIFICATION forming part of Letters Patent No; 622,344, dated April 4, 1899.

Application filed October 24,1898. Berle-1N0. 694,488. Glomodel.)

. 5'0 all whom it mag concern.-

Be it knc on that I, FREDERICK W. qoRDoN, of Philadelphia, Philadelphia county,Pen'nsylvania, have invented certain new and useful Improvements in Valves for Compressors, (Case 13,) of which the following is a specification.

This invention was patented in Great Britain October 14, 1898, No. 21,647 in France October 14, 1898, No. 282,142; in Belgium October'l i, 1898, No. 138,395, and an application for patent was filed in Germany October 14, 1898, which German application has not yet been allowed.

This invention pertains to discharge-valves ior fluid-compressors and will be readily understood from the following descriptiomtaken in connection with the accompanying drawings, in which Figure 1 is a side elevation, part vertical section, of a compressor cylinder provided with discharge-valves embodying my present improvement; Fig. 2, an end elevation of the same; and Fig. 3, a vertical section, on an'enlarged scale, in duplication of a portion of the vertical section appearing in Fig. 1.

The compressor shown is double-acting and supplied with one of the improved dischargevalves at each end. Ihe two valves being alike,-the description will be confined to the singular.

In the drawings, 1 indicates the compressorcylinder; 2, the cylinder-head; 3, the compressor-piston; 4, its piston-rod; 5, a discharge-chamber formed in the cylinder-head; 6, the discharge-outlet from said chamber; 7,

a valve-cylinder formed within the cylinder head, its axis being parallel with that of the compressor-cylinder and the inner end of the valve-cylinder being fully open to the compressor-cylinder; 8, a circumferential series of ports placing discharge-chamber 5 incommunication with valve-cylinder 7; 9, an enlargement at the outer end of valve-cylinder 7, this enlargement forming a cushion-cylinder and having a bonnet at its outer end;

10, a valve-piston fitting valve-cylinder 7, its

inner end being adapted to open and close ports 8, the valve-piston being closed-that is to say, no fluid passes through it--and thec inner end' of the valve-piston being adapted at the inner extremity of its stroke to be about flush with the inner surface of cylinder-head 2 of the compressor; 11, a rocker tappet adapted to engage the outer end of the stem of the valve=piston; 12, a wrist-plate; 13, a wrist by means of which the wrist-plate may be rocked-as, for instance, by means of a rod from an eccentric on the shaft of the compressor engine; 14, a link connecting the wrist-plate with rocker 11; 15, inlet-chamber in the cylinder-head, wherein may be located the inlet valves for the compressor, with which inlet-valves, however, my present invention is notconcerned; 16, the cushion= piston, working in cushion-cylinder 9. and

shown as an integral enlargement on the outer 1 end of valve-piston 10; 17, cushion-ports leading from discharge-chamber 5 to near the outer end of cushion-cylinder 9 and adapted to be overrun and closed by piston 16 at its outer extremity of movement; 18, similar cushion-ports adapted to be overrun by piston 16 at its inner extremity of motion 19, the stem of the valve-piston, the same projecting out through a suitable stufling-box in the bonnet, its outer end being in position to be engaged'by tappet 11; 20, an L-shaped-- packing-ring seated in agroove in the inner end-of valve-piston 10, the inner edge of this ring, that end toward the compressor-cylinder, forming the functional valve edgeof the valve-piston in cooperating with ports 8;

21, a packing-ring of rectangular section seated in the angle of ring 20, and 22 a flange seated against the inner end of the valve-piston and clamped thereto by the valve-stem, this flange forming one wall for the groove in which the packing-rings are seated and the diameter of the flange being less than that of the valve-cylinder, so as not to interfere with the functional performance of the edge of the packing-ring 20 in cooperating with the inner ends of ports 8, or, in other words, flange 22 does not add to the functional length of the valve-piston.

While the peculiarities. of the packing do not form the'subject-matter of claims herein and while other forms of packing may be employed and while packing-rings may in some cases be entirely dispensed with, it may not be out of place to explain that rings 20 and 21 are each sawed open and so doweled to the valve-piston that the sawed cut in one of the rings will traverse one of the bridges separating ports 8, while the cut in the other ring traverses another one of the bridges, the two bridges thus traversed by the cuts in the packing-rings being preferably at or near the bottom of the valve-cylinder.

Motion is to be given to rocker 11 in such manner and time that when compressor-piston 3 has completed its compressive stroke and is ready to start on its suction-stroke the valve-piston will be pushed to at least lineand-lineposition of closure, the rocker hav ing only this duty to perform. At the time this mechanical closure of the valve takes place the valve is in equilibrium, and conse-- quently the tappet requires only to overcome the mechanical friction of the valve. The drawings show the valve as thus having been pushed to line-aud-line position of closure by the action of the rocker.

Referring to Fig. 1, the valve being in lineand-line position the compressor-piston 3 starts to the right. Fluid in the clearancespace of the compressor-cylinder expands as the compressor-piston moves to the right, and when the pressure in the compressor-cylinder shall by expansion have been reduced sufficiently the preponderating pressure in' the discharge-chamber 5, acting on the left ofthe valve-piston, will overcome the mechanical friction of the valve and suddenly move it to the right to position of full lap, any shock of 5 the movement being checked by the cushioning action of piston 16 verrunning ports 18. The valve, having gone to position of full lap,

. remains held in that position by the preponderating pressure in the discharge-chamber, and under these conditions the compressorpiston makes its suction stroke, the compressor-cylinder becoming filled'with fluid at pressure of reception-atmospherie pressure in case of simple compressors and greater pressure in the case of the second element of a compound compressor. The compressorpiston, being at the extreme right, starts on its compression-stroke, the valve being still closed. As compression takes place in the compressor-cylinder the pressure of the fluid therein approaches and reaches and finally exceeds that in the discharge-chamber. When the excess of pressure in the compressor-cylinder shall have become sutlieienttooverco'me the mechanical friction of the valve,}thenthe valve will suddenly move to the left to full open position, the shock of the movement being checked by the cushioning action of piston 16 overrunning ports 17. The com ressed fluid now passes to the discharge-e amber through the inner end of the valve-cylinder and through ports 8. Upon the completion I of the compressive stroke in question and as the piston begins its following suction-stroke the tappet has pushed the valve to line-andline position, as before.

As before mentioned, the valve will move It is tobe observed in Fig. 1 that the inner end of the valve-piston stands a trifle at the left away from the inner face of the cylinderhead, the valve being in line-and-line position. When the valve moves to the right,

going to full lap, the inner end of the valve-' piston'is about flush withthe inner face of the cylinder-head. Consequently there is but a minimum of clearance chargeable to the discharge-valve system. These valves have the advantage of simplicity of construction, smoothness of action, ready accessibility, easy repair, perfection of control in time of opening, and they particularly lend themselves to closing actuation from a simple eccentric on the engine-shaft.

I'elaim as my invention- 1. The combination, substantially as set forth, of a compressor-cylinder, a valve-cylinder with an end' opening directly to the compressor cylinder and having discharge ports in its wall near such end, the opposite end of said valve-cylinder being in communication with the discharge-chamber, a closed valve-piston fitted to reciprocate within said valvecylinder and to have its end cooperate with said discharge-ports, and a tappet adapted to move said valve-piston to position to cover said ports.

2. The combination, substantially as set forth, of a compressor-cylinder, a valve-cylinder with an end opening directly to the compressor-cylinder and having dischargeports in its wall near such end, the opposite end of said valve-cylinder being in communication with the dischargo-ehamber, a closed valve-piston fitted to reciprocate within said valve-cylinder. and to have its end cooperate with said discharge-ports, a tappet adapted to move said valve-piston to position to cover said rts, and a cushioning-piston connected with said valve-piston.

3. A valve for compressors, comprising a valve-cylinder open at one end, dischargeports in the wall of said valve-cylinder near its open end, a cushioning-cylinder formed by a concentric enlargement at the opposite end of the valve-cylinder, cushioning-ports in the wall of saidcushioning-chamlwr near its ends, a closed valve-piston fitting within said valve-cylinder and adapted to have its end cooperate with said first-mentioned ports, an enlargement on the opposite end of said valve-piston fitting said cushioning-cylinder and adapted to overrun and close said cushioning-ports, and a'tappet adapted to move B im rivzaiL-i' iliilitii GQPY said valve-piston to position to elose the firstmentioned ports, combined substantially as and for the purpose set forth.

4. The combination, substantially as set forth, of a compressor cylinder, cylinderheads therefor containing discharge-chambers, a valve-cylinder in each head opening directly into the compressor-cylinder and having discharge-ports communicating with T0 the respective discharge-chambers, a closed valve-piston in each of saidvalve-cylinders, a tappet-rocker at each of said cylinder-heads and adapted to move its appropriate valvepiston to position of closure, a wrist-plate,

and links connecting said tappet-roekers with I 5 

